Damper apparatus for transport refrigeration system, transport refrigeration unit, and methods for same

ABSTRACT

Embodiments of systems, apparatus, and/or methods can provide a damper assembly for transport refrigeration systems. One embodiment can include a damper assembly including a damper door configured to operate in a first position (e.g., closed), a second position (e.g., open), and at least one intermediate position. In one embodiment, a plurality of intermediate positions can be used to controllably vary a capacity of the transport refrigeration unit, or at least one component thereof. Embodiments of systems, apparatus, and/or methods can provide a damper assembly that can be accessed though an ambient portion of transport refrigeration systems or components.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/234,858 entitled “Damper Apparatus for TransportRefrigeration System, Transport Refrigeration Unit, and Methods forSame” filed on Aug. 18, 2009 and U.S. Provisional Patent ApplicationSer. No. 61/247,791 entitled “Damper Apparatus for TransportRefrigeration System, Transport Refrigeration Unit, and Methods forSame” filed on Oct. 1, 2009. The content of these applications areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates generally to the field of transport refrigerationsystems and methods of operating the same.

BACKGROUND OF THE INVENTION

A particular difficulty of transporting perishable items is that suchitems must be maintained within a temperature range to reduce orprevent, depending on the items, spoilage, or conversely damage fromfreezing. A transport refrigeration unit is used to maintain propertemperatures within a transport cargo space. The transport refrigerationunit can be under the direction of a controller. The controller ensuresthat the transport refrigeration unit maintains a certain environment(e.g. thermal environment) within the transport cargo space. Thecontroller can operate a transport refrigeration system including adamper assembly.

SUMMARY OF THE INVENTION

In view of the background, it is an object of the application to providea transport refrigeration system, transport refrigeration unit, andmethods of operating same that can maintain cargo quality by selectivelycontrolling transport refrigeration system components.

One embodiment according to the application can include a control modulefor a transport refrigeration system. The control module includes acontroller for controlling the transport refrigeration system to operatea damper.

In an aspect of the invention, a transport refrigeration unit includes atransport refrigeration unit operatively coupled to an enclosed volume.A conditioned portion of the transport refrigeration unit to include asupply port to output air to said enclosed volume at a supplytemperature, a return port to return air from said enclosed volume tothe transport refrigeration unit at a return temperature, an air flowbetween the return port and the supply port and a damper door tooperatively block the air flow in a first position and pass the air flowin a second position. The transport refrigeration unit to include atleast one component outside the conditioned portion and configured tomove the damper door to or from the first position.

In an aspect of the invention, a transport refrigeration unit includes adamper on a first side of an insulation barrier to operatively block airflow in a defrost mode in first position. The transport refrigerationunit to include at least one component on the opposite side of theinsulation barrier configured to repeatedly move the damper door fromthe first position during one defrost mode. In one embodiment, the atleast one component is in an ambient environment of the transportrefrigeration unit.

In an aspect of the invention, a transport refrigeration unit includes atransport refrigeration unit to operatively couple to an enclosedvolume. The transport refrigeration unit to include a blower assemblyand a supply port to output an air flow at prescribed conditions. Thetransport refrigeration unit to include a damper to operatively blockthe air flow in a first position and pass the air flow in a secondposition. The transport refrigeration unit to include at least onecomponent configured to controllably reciprocally move the damper doorbetween the first position and the second position and to controllablystop the damper door at a plurality of positions between the firstposition and the second position.

In an aspect of the invention, a transport refrigeration unit includes atransport refrigeration unit to operatively couple to a cargo container.A refrigerated portion of the transport refrigeration unit to include afirst port to output air from an evaporator at a first temperature, asecond port to provide air to the evaporator at a second (e.g., higher)temperature, a passageway between the first port and the second port, anevaporator and a damper serially positioned in the passageway betweenfirst port and the second port so that the first port can not output theair from the evaporator when the damper is in a first position. Thetransport refrigeration unit to include at least one component outsidethe refrigerated portion and operatively coupled to the damper in thepassageway.

In an aspect of the invention, a transport refrigeration unit caninclude a compressor, a condenser downstream of the compressor, anexpansion device downstream of the condenser, and an evaporatordownstream of the expansion device, the transport refrigeration unitincluding a barrier to separate an first portion of the transportrefrigeration unit to operate in a refrigerated environment from asecond portion, the evaporator in the first portion, at least one damperdoor in the refrigerated portion, and an actuator operatively coupled tomove the damper door, the actuator is positioned in the second portion.

In an aspect of the invention, a transport refrigeration unit caninclude a first portion of the transport refrigeration unit to beconditioned, a damper in the conditioned first portion to block aprescribed air flow, and a damper actuator operatively coupled to thedamper, the damper actuator to be accessible outside the transportrefrigeration unit without exposing the first portion to be conditioned.

In an aspect of the invention, a method of modifying a transportrefrigeration unit having a thermal barrier between a refrigeratedportion and an ambient portion can include providing an evaporator on arefrigerated side of the thermal barrier; and installing an actuator fora damper on the ambient side of the thermal barrier.

In an aspect of the invention, a damper assembly for a transport unitincluding a refrigeration system, the damper assembly can include athermal housing for insulating a conditioned space, at least one dampershaft passing though the thermal housing, and an actuator coupled to thedamper shaft to move the damper shaft between an open position and aclosed position.

In an aspect of the invention, a transport refrigeration unit caninclude a compressor, a primary refrigerant circuit including heatrejection heat exchanger downstream of the compressor, and a heatabsorption heat exchanger downstream of the heat rejection heatexchanger, the transport refrigeration unit including a barrier toseparate a first portion of the transport refrigeration unit to operatein a refrigerated environment from a second portion, and at least onedamper door in the refrigerated portion, the damper door to move betweenthree or more positions.

In an aspect of the invention, a transport refrigeration unit caninclude an evaporator connected within the transport refrigeration unit,a damper configured to selectively block a prescribed air flow incommunication with the evaporator, at least one sensor operativelycoupled to the damper, and a controller coupled to the sensor todetermine when the damper is in an intermediate position between a firstposition and a second position.

In one aspect of the invention, a method of modifying a transportrefrigeration unit including a damper assembly can include configuringthe damper to operate in a first position in a first mode of thetransport refrigeration unit, and configuring the damper to vary asystem capacity in a second mode of the transport refrigeration unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Novel features that are characteristic of exemplary embodiments of theinvention are set forth with particularity in the claims. Embodiments ofthe invention itself may be best be understood, with respect to itsorganization and method of operation, with reference to the followingdescription taken in connection with the accompanying drawings in which:

FIG. 1 is a diagram that shows an embodiment of a transportrefrigeration system according to the application;

FIG. 2 is a diagram that shows an embodiment of a transportrefrigeration system according to the application;

FIG. 3 is a diagram that shows an embodiment of a transportrefrigeration system according to the application;

FIG. 4A is a diagram that shows an embodiment of a transportrefrigeration system according to the application;

FIG. 4B is a diagram that shows an exemplary schematic cross-sectionalview of a portion of FIG. 4A;

FIG. 5 is a diagram illustrating a perspective disassembled view of adamper according to an embodiment of the application;

FIG. 6 is a diagram illustrating a perspective disassembled view of adamper according to an embodiment of the application;

FIG. 7 is a diagram illustrating an exemplary embodiment of a damperassembly according to another embodiment of the application;

FIG. 8 is a diagram illustrating an exemplary embodiment of a seal foruse with the damper assembly of FIG. 7;

FIG. 9 is a diagram illustrating a cross-sectional view of a damperaccording to an embodiment of the application;

FIGS. 10A-10B are diagrams illustrating an embodiment of a damperassembly for a transport refrigeration system according to theapplication; and

FIG. 11 is a diagram that shows an exemplary representative sensor foruse with a damper assembly according to embodiments of the application.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of theapplication, examples of which are illustrated in the accompanyingdrawings. Whenever possible, the same reference numerals will be usedthroughout the drawings to refer to the same or like parts.

FIG. 1 is a diagram that shows an embodiment of a transportrefrigeration system. As shown in FIG. 1, a transport refrigerationsystem 100 can include a transport refrigeration unit 10 coupled to anenclosed space within a container 12. The transport refrigeration system100 may be of the type commonly employed on refrigerated trailers. Asshown in FIG. 1, the transport refrigeration unit 10 is configured tomaintain a prescribed thermal environment within the container 12 (e.g.,cargo in an enclosed volume).

In FIG. 1, the transport refrigeration unit 10 is connected at one endof the container 12. Alternatively, the transport refrigeration unit 10can be coupled to a prescribed position on a side or more than one sideof the container 12. In one embodiment, a plurality of transportrefrigeration units can be coupled to a single container 12.Alternatively, a single transport refrigeration unit 10 can be coupledto a plurality of containers 12 or multiple enclosed spaces within asingle container. The transport refrigeration unit 10 can operate toinduct air at a first temperature and to exhaust air at a secondtemperature. In one embodiment, the exhaust air from the transportrefrigeration unit 10 will be warmer than the inducted air such that thetransport refrigeration unit 10 is employed to warm the air in thecontainer 12. In one embodiment, the exhaust air from the transportrefrigeration unit 10 will be cooler than the inducted air such that thetransport refrigeration unit 10 is employed to cool the air in thecontainer 12. The transport refrigeration unit 10 can induct air fromthe container 12 having a return temperature Tr (e.g., firsttemperature) and exhaust air to the container 12 having a supplytemperature Ts (e.g., second temperature).

In one embodiment, the transport refrigeration unit 10 can include oneor more temperature sensors to continuously or repeatedly monitor thereturn temperature Tr and/or the supply temperature Ts. As shown in FIG.1, a first temperature sensor 24 of the transport refrigeration unit 10can provide the supply temperature Ts and a second temperature sensor 22of the transport refrigeration unit 10 can provide the returntemperature Tr to the transport refrigeration unit 10, respectively.Alternatively, the supply temperature Ts and the return temperature Trcan be determined using remote sensors.

A transport refrigeration system 100 can provide air with controlledtemperature, humidity or/and species concentration into an enclosedchamber where cargo is stored such as in container 12. As known to oneskilled in the art, the transport refrigeration system 100 (e.g.,controller 250) is capable of controlling a plurality of theenvironmental parameters or all the environmental parameters withincorresponding ranges with a great deal of variety of cargos and underall types of ambient conditions.

FIG. 2 is a diagram that shows an embodiment of a transportrefrigeration system. As shown in FIG. 2, a transport refrigerationsystem 200 can include a transport refrigeration unit 210 coupled to acontainer 212, which can be used with a trailer, an intermodalcontainer, a train railcar, a ship or the like, used for thetransportation or storage of goods requiring a temperature controlledenvironment, such as, for example foodstuffs and medicines (e.g.,perishable or frozen). The container 212 can include an enclosed volume214 for the transport/storage of such goods. The enclosed volume 214 maybe an enclosed space having an interior atmosphere isolated from theoutside (e.g., ambient atmosphere or conditions) of the container 212.

The transport refrigeration unit 210 is located so as to maintain thetemperature of the enclosed volume 214 of the container 212 within apredefined temperature range. In one embodiment, the transportrefrigeration unit 210 can include a compressor 218, a condenser heatexchanger unit 222, a condenser fan 224, an evaporation heat exchangerunit 226, an evaporation fan 228, and a controller 250. Alternatively,the condenser 222 can be implemented as a gas cooler.

The compressor 218 can be powered by single phase electric power, threephase electrical power, and/or a diesel engine and can, for example,operate at a constant speed. The compressor 218 may be a scrollcompressor, a rotary compressor, a reciprocal compressor, or the like.The transport refrigeration system 200 can use power from, and can beconnected to a power supply unit (not shown) such as a standardcommercial power service, an external power generation system (e.g.,shipboard), a generator (e.g., diesel generator), or the like.

The condenser heat exchanger unit 222 can be operatively coupled to adischarge port of the compressor 218. The evaporator heat exchanger unit226 can be operatively coupled to an input port of the compressor 218.An expansion valve 230 can be connected between an output of thecondenser heat exchanger unit 222 and an input of the evaporator heatexchanger unit 226.

The condenser fan 224 can be positioned to direct an air stream onto thecondenser heat exchanger unit 222. The air stream from the condenser fan224 can allow heat to be removed from the coolant circulating within thecondenser heat exchanger unit 222.

The evaporator fan 228 can be positioned to direct an air stream ontothe evaporation heat exchanger unit 226. The evaporator fan 228 can belocated and ducted so as to circulate the air contained within theenclosed volume 214 of the container 212. In one embodiment, theevaporator fan 230 can direct the stream of air across the surface ofthe evaporator heat exchanger unit 226. Heat can thereby be removed fromthe air, and the reduced temperature air can be circulated within theenclosed volume 214 of the container 212 to lower the temperature of theenclosed volume 214.

The controller 250 such as, for example, a MicroLink.™ 2i controller orAdvance controller available from Carrier Corporation of Syracuse, N.Y.,USA, can be electrically connected to the compressor 218, the condenserfan 224, and/or the evaporator fan 228. The controller 250 can beconfigured to operate the transport refrigeration unit 210 to maintain apredetermined environment (e.g., thermal environment) within theenclosed volume 214 of the container 212. The controller 250 canmaintain the predetermined environment by selectively controllingoperations of the condenser fan 224, and/or the evaporator fan 228 tooperate at a low speed or a high speed. For example, if increasedcooling of the enclosed volume 214 is required, the controller 250 canincrease electrical power to the compressor 218, the condenser fan 224,and the evaporator fan 228. In one embodiment, an economy mode ofoperation of the transport refrigeration unit 210 can be controlled bythe controller 250. In another embodiment, variable speeds of components(e.g., compressor 218) of the transport refrigeration unit 210 can beadjusted by the controller 250. In another embodiment, a full coolingmode for components of the transport refrigeration unit 210 can becontrolled by the controller 250. In one embodiment, an economizercircuit can be included in the transport refrigeration unit. In oneembodiment, the electronic controller 250 can adjust a flow of coolantsupplied to the compressor 218.

FIG. 3 is a diagram that shows an embodiment of a transportrefrigeration system. As shown in FIG. 3, transport refrigeration system300 can include a transport refrigeration unit 310 coupled to anenclosed space 314 within a container 312. As described herein, thetransport refrigeration systems, transport refrigeration modules,components and methods for controlling the same can operate in a coolingmode and a heating mode depending at least in part upon the temperatureof the conditioned space and the ambient temperature of the environmentoutside the enclosed space 314. Air that is cooled or heated by thetransport refrigeration system 300 can be drawn by a fan (e.g., blowerassembly), conditioned and discharged into the enclosed space 314.

In one embodiment, the transport refrigeration unit 310 can beconsidered to have a first refrigerated (e.g., conditioned) portion foroperative coupling to the enclosed space 314 and a second ambient (e.g.,not conditioned) portion that is insulated from the enclosed space 314(and the first refrigerated portion). For example, an evaporator 326 andevaporator fan 328 can be in the first refrigerated portion and acondenser 322 and a condenser fan 324 can be in the second ambientportion of the transport refrigeration unit 310. A first wall 340 (e.g.,physical and/or thermal barrier) can be positioned between the firstrefrigerated portion and the second ambient portion.

As shown in FIGS. 3-4B, the transport refrigeration unit 310 is incommunication with the enclosed space 314 via a first opening 350 and asecond opening 355 to maintain the enclosed volume 314 at predeterminedconditions (e.g., temperature, humidity, etc.) during transportation andstorage in order to preserve the quality of the cargo. The first opening350 and the second opening 355 can be in a first compartment wall 345configured to face or be operatively coupled to the enclosed space 314.A compartment 330 can enclose the transport refrigeration unit 310. Asshown in FIG. 3, the compartment 330 is shown as a rectangular box;however, the exterior shape of the compartment 330 can vary as known toone skilled in the art. Generally, the transport refrigeration unit 310is operable in a refrigeration mode (e.g., a cooling mode, a heatingmode) and a defrost mode, and includes one or more refrigerationcomponents (not entirely shown), such as an evaporator 336, one or morecompressors, a condenser, one or more fans, a receiver, and one or moreexpansion valves to route refrigerant through the transportrefrigeration unit 310. Such arrangements are known in the art.

The transport refrigeration system 300 can operate in a defrost mode tolimit formation of ice and/or frost in the transport refrigeration unit310 (e.g., on an evaporator). During operation, exemplary transportrefrigeration systems direct heat toward the evaporator 336 in thedefrost mode. A warming evaporator 336 can also warm the air around ornearby the evaporator 336 in the defrost mode. For example, relativelywarm refrigerant can be directed through the evaporator 336. In someexisting transport units, the unit 310 can be operated in reverse suchthat heat is generated in the evaporator 336 (not the condenser/gascooler) in a defrost mode. Alternatively, during the defrost mode, heatcan be supplied from the condenser 328 to the evaporator 326 (e.g., viaconfigurable ducting). Also, ambient air or a heater can be used to heatthe evaporator 336. Further, a resistive device can be co-located withthe evaporator 326 such that when power is applied across the resistivedevice in the defrost mode, heat is supplied to the evaporator 326.Equivalent methodologies and/or apparatus are known to one of ordinaryskill in the art to defrost an evaporator in a refrigeration transportunit; and all equivalent methodologies and/or apparatus are consider tofall within the scope of the application.

The compartment 330 can include the first wall 340 that separatescomponents (e.g., condenser 322) of the transport refrigeration unit 310that remain in an ambient environment mutually exclusive from theenclosed space 314 and/or the first refrigerated portion of the unit310. The first wall 340 and the first compartment wall 345 can determinea three dimensional passageway 360 (e.g., thermal housing, thermalcompartment) therebetween to connect the first opening 350 and thesecond opening 355. In one embodiment, the first compartment wall 345determines a front of the passageway 360, the first wall 340 candetermine a rear of the passageway 360 and sides of the compartment 330can determine opposing side walls of the passageway 360 that physicallyconnect the first compartment wall 345 and the first wall 340. However,other configurations can be used to form the passageway 360. Forexample, inner side portions or walls of the container 312 can beprovided as side walls of the passageway 360 or the first wall 340and/or the first compartment wall 345 can have a three dimensional shapeto provide the side walls of the passageway by direct connectiontherebetween.

The evaporator 326 can be positioned in the passageway 360 behind thefirst compartment wall 345, and is in communication with the enclosedspace 314 through an air flow 352 between the first opening 350 and thesecond opening 355. In one embodiment, the passageway 360 cansequentially include the evaporator 326 and a damper 375 between thefirst opening 350 (e.g., return air) and the second opening 355 (e.g.,supply air). In one embodiment, the evaporator fan 328 is in thepassageway 360 between the evaporator 326 and the damper 375.Alternatively, the evaporator fan 338 can be operably coupled to thepassageway 360 anywhere between the first opening 350 and the secondopening 355 to move air from the first opening 350 (e.g., from theenclosed space 314), across a surface of the evaporator 326, past thedamper 375, and through the second opening 355 (e.g., to the enclosedspace 314).

As shown in FIG. 4A, the damper 375 can be placed downstream of the fan328 to reduce or inhibit heat and/or warm air that is discharged from ormoved by the fan 328 during the defrost mode from exiting via the secondopening 355 to enter the conditioned space. In one embodiment, thedamper 375 is an airtight barrier or a plate that is in an open positionwhen the refrigeration system is in the cooling or heating modes, and ismoved to a closed position when the refrigeration system is in thedefrost mode. In one embodiment, the damper 375 can pivot or rotatebetween the open and closed positions about an axis that can be locatedbetween a front end and a rear end (e.g., longitudinal) of the damper375.

FIGS. 5-6 are diagrams that show that the transport refrigeration unit310 can also include damper assembly 370, which can include a damperactuator 372, a damper support 374, and the damper 375. FIGS. 5 and 6show that the actuator 372 is behind the first wall 340 in the secondambient portion outside the first refrigerated portion. The damper 375can be positioned in the passageway 360 in the first refrigeratedportion adjacent the second opening 355. The damper actuator 372 is onopposite sides of the first wall 340 from the damper 375.

As illustrated in FIGS. 5-6, the damper support 374 can pass through thefirst wall 340 to rigidly support opposite ends of the damper 375 in thepassageway 360. The actuator 372 is operatively coupled to the damper375 through the damper support 374 to move the damper 375 between aclosed position blocking the second opening 355 and a first position(e.g., open position shown in FIG. 6). Accordingly, the damper support374 can include any number of linkages, bearings, connectors, fasteners,shafts, cams, etc. to mechanically operatively couple the actuator 372to the damper 375. The actuator 372 can include any number of devicesthat can supply force used to move the damper 375 such as but notlimited to a linear actuator, mechanism, piston, power train, or amanual operation. In one embodiment, the actuator 372 can be anelectrical motor that is in communication with a power source (e.g.,battery, etc.) of the transport refrigeration unit 310, although otherprime movers are also possible and considered herein. FIGS. 5-6 show anexemplary 3-D shape of the first wall 340.

The damper 375 can be a roughly rectangular shaped when viewed fromabove/below with a front end 390, opposing sides 392 and a back end 395.In the closed position, the damper 375 can have the front end 390,opposing sides 392 and back end 395 blocking passageway 360 (e.g., thesecond opening 355). At least one of the front end 390, opposing sides392 and back end 395 can include resilient seals or the like as known toone skilled in the art to reduce air flow around the damper 375 in theclosed position, to make the closed position of the damper 375 airtightand/or to reduce airflow interference in an open position.

As described herein, a transport refrigeration unit 310 can include adamper assembly 370 to operatively block air flow in a defrost mode(e.g., the damper assembly in a first configuration). In one embodiment,a controller 350 of the unit 310 can operate to controllably transitionthe unit 310 into and/or out of the defrost mode. The damper assembly370 can include at least one component (the actuator 372 and/or dampersupport 374) outside the conditioned space (or on an opposite side ofthe first wall 340) and configured to repeatedly move the damper doorfrom a prescribed position (e.g., closed, open) during one defrost mode.Moving the damper 375 position periodically during defrost or otheroperational times when ice is likely to build up can reduce thelikelihood of the damper 375 freezing in place or freezing in oneposition. Further, repeatedly moving the damper 375 position duringdefrost or other operational times when ice can form and can reducetorque requirements of the actuator 372. In one embodiment, repeatedly“jogging” the damper assembly can occur periodically, aperiodically,intermittently, upon operator action or responsive to a sensedcondition.

In one embodiment, the damper actuator 372 can comprise a positionsensor that can be correlated to determine a position of the damper 375.For example, when the actuator 372 is a motor, the position sensor canbe used to determine an angle of rotation of the motor using apotentiometer, optical sensor or the like to generate a signal that canbe transmitted to the controller 350. In one embodiment, the actuator372 can be operated in steps that can be correlated to a plurality ofpositions between a closed position and an open position of the damper.An exemplary damper can be moved in steps between open and closed orselected prescribed positions. According to embodiments of theapplication, a damper can be selectively driven (e.g., directly) to oneof a plurality of intermediate positions (e.g., 5 positions, 25positions, 50 positions, or more) between open and closed.

FIG. 7 is a diagram that shows an exemplary embodiment of a damperassembly 700 according to the application. The damper assembly 700 canbe used as the damper assembly 370; however, embodiments according tothe application are not intended to be limited thereto.

As shown in FIG. 7, a damper assembly 700 can include an actuator 710operatively coupled through support 715 and first shaft 720 to a manualoverride coupler 725. The first shaft 715 can be driven by and/or bepart of the actuator 710. In one embodiment, the actuator 710 functionsto move the damper 775 between an open position and a closed position.The manual override coupler 725 connects the first shaft to the dampersupport shaft 730. The manual override coupler 725 has at least twoopposing flat surfaces (e.g., a hex nut configuration) for connection toa wrench (not shown) to provide an additional capability (e.g., a user)to move the damper 775 between the open and closed position. The manualoverride coupler 725 can allow a limp home capability when the defrostmode of the transport refrigeration system 300 (e.g., actuator 710) isnot operational to re-open a closed damper 775. Thus, the damperassembly 700 can provide a manual damper opening or closing operationaccessible from the second ambient portion of the compartment 330.

Embodiments of a transport refrigeration unit, damper assembly, andmethods for same can provide an ability to service a damper actuator(e.g., replace a motor) without affecting the damper, from the ambientside of the unit 310, without disturbing a loaded cargo, or removing theunit 310 from the container 312. In one embodiment, the actuator can beaccessed through a door of the unit 310 or an access panel on theambient side of the thermal insulation wall or the ambient side ofcompartment 330. Similarly, a bearing support (e.g., brace 750, shaft730, 730′, etc.) for the damper can be accessed through the ambient sideof the unit 310.

The damper support shaft 730 is coupled to the manual override coupler725 to pass from the ambient side of first wall 340 to the conditionedside of the unit 310 and the passageway 360 in the first refrigeratedportion. In the passageway 360, the damper support shaft 730 can form orconnect to an attachment portion 735. The attachment portion 735corresponds to an engagement portion 776 of the damper 775. Theattachment portion 735 and the engagement portion 776 of the damperoperate to integrally connect to the damper 775 to the damper supportshaft 730.

In one embodiment, the damper support shaft 730 can be a cylindricalshaft having a portion removed at the attachment portion 735 to providea flat engagement surface (e.g., a half-cylinder) and the engagementportion 776 can be glued or affixed to the flat engagement surface. Theengagement portion 776 of the damper 775 can include inserts that extendinto the damper 775 from one side to the other side of the damper 775(and/or attachment portion 735) so that the inserts can receivefasteners (e.g., bolts, screws, etc.) that attach the attaching portion735 to the engagement portion 776 of the damper 775. In embodiments inwhich the damper 775 is formed by a molding process, the inserts can beco-molded into the damper. Equivalent methodologies are known to one ofordinary skill in the art to couple or rigidly connect the damper 775and the damper support shaft 730 and all equivalent methodologies areconsidered to fall within the scope of this application.

The support shaft 730 can directly pass through the first wall 340 or anadditional support member 740 can be provided. For example, theadditional support member 740 can be a hollow cylinder sized to pass theouter diameter of the damper shaft 730 and function to reduce oreliminate thermal (e.g., conditioned air loss) loss though the hole inthe first wall 340 passing the damper support shaft 730. In addition, agasket (not shown) or the like can be provided between the first wall340 and the damper support shaft 730, 730′.

As shown in FIG. 7, the damper 775 can be a uniformly thick structure.However, the damper 775 can be tapered or the like. In one embodiment,the damper 775 can be metal; however, other materials having asufficient rigidity to hold a configuration under the range of air flowpressures through the passageway 360 such as selected plastics, alloys,polymers or the like can be used. Further, the damper 775 is shown as asingle unitary piece. However, the damper 775 can be a plurality ofseparate damper doors provided side-to-side or front-to-back.Alternatively, the damper 775 can be a series of overlapping portions toincrease structural support. Equivalent methodologies are known to oneof ordinary skill in the art to form the damper 775, and all equivalentmethodologies are considered to fall within the scope of the presentapplication.

As shown in FIG. 7, the damper support shaft 730 can include twoseparate portions 730, 730′ rigidly and rotatably connected by thedamper 775. After the second portion of the damper support shaft 730′passes from the passageway 360 through the first wall 340 to the secondambient portion, the damper support shaft 730′ can be coupled to a brace750. In one embodiment, the brace 750 includes a bracket having a firstportion 752 fixed by fasteners 751 to a support structure, e.g., thefirst wall 340. The second portion of the damper shaft 730′ can berotatably attached by a brace mount 754 and by fasteners 751 to a secondportion 753 of the bracket 750 that is perpendicular to the firstportion 752. In one embodiment, the damper support shaft 730, 730′ canbe provided as a single piece that extends between the engagementportion 776 across the width of the damper 775. The actuator 710 can bemounted to the first wall 340 by a bracket (not labeled). In oneembodiment, a second actuator can be drivingly connected to the dampersupport shaft 730′ instead of the brace 750. The brace 750 can beaccessed through the second ambient portion (e.g., an access panel incompartment 330) of the unit 310.

FIG. 8 is a diagram that shows an exemplary seal for use with the damperassembly of FIG. 7 according to the application. As shown in FIG. 8, aretractable bellows seal 810 can seal the damper support shaft 730 tothe actuator 710. The retractable bellows seal 810 can reduce or preventair from the enclosed space 314 from escaping through the passageway 360and the first wall 340 to the second ambient portion in the compartment330. In one embodiment, the retractable bellows seal 810 is coupled by afirst connector 820 to the support member 715 of the actuator 710 and bya second connector 830 to the additional support member 740. The firstconnector 820 and second connector 830 can be a tightnable adjustmentband having a circumference reduced by a corresponding tangential screw840. However, other fasteners as known to one skilled in the art may beused to connect the bellows seal 810 between the actuator 710 and thefirst wall 340. To access and operate the manual operation coupler 725,one end of the retractable bellow seal 810 is released and slid over thecoupler 725. Then, manual force can be applied to open or shut thedamper 775 (e.g., when the actuator 710 is not operational).

FIG. 9 is a diagram illustrating a perspective cross-sectional view of adamper according to embodiment of the application. As shown in FIG. 9,the damper shaft 730 can define a pivot axis 925 so that the damper 775is pivotable about the pivot axis 925 between the open position and theclosed position. As shown in FIGS. 7 and 9, the pivot axis 925 is offsetfrom a center of the damper 775 between the first end 790 and the secondend 795. In one embodiment, the second end 795 is closer to the pivotaxis 928 than the first end 790. The axis 925 can be vertically offsetso that when the damper 775 is in the closed position, the first end 790can be engaged with the lower surface of the passageway 360 and thesecond end 795 can be engaged with an upper surface of the passageway360.

In one embodiment, the open position of the damper 775 can be controlledby the actuator 710 moving the damper 775 until physically blocked by atleast one stop member 910. As shown in FIG. 9, in a portion of thepassageway 360 surrounding the damper 775 can include an upper surface940, lower surface 930 and opposing side surface 935 that encompass theair flow 352. The stop members 910 are coupled to the side surface 935.However, the stop members 910 can be configured to extend from or mountto the upper surface 940 or the lower surface 930. Each stop member 910extends inward from the corresponding side surface 935, and is spacedapart from the upper surface 940 so that when the damper 775 is in theopen position, the damper 775 extends approximately parallel to theupper surface 940 (that can be sloped, curved, non-linear, etc.) todirect the airflow from the evaporator fan efficiently through thesecond opening 355. In one embodiment, the stop members 910 can bespaced apart from the upper wall portion 940 so that when the damper 775is in the open position, the damper 775 extends slightly downward awayfrom or slightly upward toward the upper surface 940.

In one embodiment, a duct unit 990 can be positioned between the damper775 and the second opening 355 in the passageway 360 to controllablydirect conditioned air out of the second opening 355 and/or into theenclosed space 314.

In operation, the evaporator fan 328 generates the airflow 352 throughthe passageway 360 and into the enclosed space 314 when the transportrefrigeration unit 310 is in the refrigeration mode. Generally, air fromthe conditioned space enters the passageway 360 from the enclosed spacethrough the first opening 350 and is conditioned by the evaporator 322,and the airflow 352 is discharged by the evaporator fan 328 toward thesecond opening 355. The airflow 352 flows outward from the evaporatorfan 328 across the damper 775 toward the second opening 355.

In some embodiments the evaporator fan 328 rotates continuously when thetransport refrigeration unit 310 (e.g., condenser 318) is operating,thereby continuously generating the airflow 352. When the transportrefrigeration unit 310 is in the defrost mode, the warm, defrostingevaporator 322 can heat air that passes over the evaporator fan 328. Thedamper 775 is pivoted to the closed position when the transportrefrigeration system 300 is in the defrost mode to inhibit flow of theheated airflow from the evaporator fan 328 into enclosed space 314. Inone embodiment, a front end or first end of the damper can contact theupper surface and the opposite end or second end can contact the bottomsurface when the damper is in the closed position and sides of thedamper 775 contact sides of the passageway 360 to more completely reduceair flow. As a result, the airflow generated by the evaporator fan 328circulates within the passageway 360 between the first wall 340 and thecompartment wall 345 generally around the perimeter of evaporator fan328 and does not pass through the second opening 355 (or the firstopening 350) into the enclosed space 314.

Embodiments of apparatus and/or methods according to the application canbe located in a conditioned air flow without interfering with and/orimpeding fan efficiency. In one embodiment, exemplary dampers can belocated adjacent or at an outlet opening to the conditioned or cargospace. Locating these dampers in the exhaust duct takes up additionalspace in the passageway. Embodiments of apparatus and/or methodsaccording to the application do not affect a size of one or morecomponents of the refrigeration system (e.g., components in theconditioned air flow, evaporator coil, compressor, etc.) and/or arefrigeration capacity of the refrigeration system.

Embodiments of the application have been described herein with referenceto a single passageway between a return air vent and a supply air vent.However, any number of first openings and second openings may be used.Further, any number of sub-passageways, associated ducts, vias can beused to form the passageway 360. Similarly, the air flow 352 can beprovided between a plurality of first openings 350 and a plurality ofsecond openings 355 such the air flow 352 engages the evaporatortherebetween and can be block by one or more corresponding damperassemblies described herein.

Embodiments of apparatus and/or methods according to the application canreduce or prevent air that is warmed by the evaporator in the defrostmode from reaching the temperature controlled cargo that can expose thetemperature sensitive cargo to adverse or undesirable conditions.

However, various cross-sections (e.g. tapered, non-liner) and shapes(e.g., rectangular) of the damper 375 can be used.

FIGS. 10A-10B are diagrams that show another embodiment of a damperassembly and a transport refrigeration system according to theapplication. As shown in FIGS. 10A-10B, transport refrigeration system1000 can include a transport refrigeration unit 1010 to couple to anenclosed space 314 within a container 312. A thermal barrier 1040 (e.g.,physical barrier) can be positioned between a first refrigerated portionoperatively coupled to the enclosed space 314 and a second ambientportion of the transport refrigeration unit 1010.

As shown in FIGS. 10A-10B, the transport refrigeration unit 1010 can bein communication with the enclosed space 314 via a first opening 1050and a second opening 1055 to maintain the enclosed volume 314 atpredetermined conditions (e.g., temperature, humidity, etc.) duringtransportation and storage in order to preserve the quality of thecargo. The first opening 1050 and the second opening 1055 can be in afirst compartment wall 1045 configured to face or be operatively coupledto the enclosed space 314. Generally, the transport refrigeration unit1010 is operable in a refrigeration mode (e.g., a cooling mode, aheating mode) and a defrost mode, and includes one or more refrigerationcomponents (not entirely shown), such as an evaporator 326, one or morecompressors, a condenser, one or more fans, such as evaporator fan 328and one or more expansion valves and a controller such as controller 350to route refrigerant through the transport refrigeration unit 1010. Sucharrangements are known in the art.

A compartment 1030 enclosing the transportation refrigeration unit 1010can include the thermal barrier 1040 that separates components (e.g.,condenser 322) of the transport refrigeration unit 1010 that remain inan ambient environment from the enclosed space 314 and/or the firstrefrigerated portion of the compartment 1030 or the unit 1010. Thethermal barrier 1040 and the first wall 1045 can determine a threedimensional passageway 1060 (e.g., housing, duct(s), thermalcompartment) therebetween to connect the first opening 1050 and thesecond opening 1055. In one embodiment, the first compartment wall 1045determines a front of the passageway 1060, the thermal barrier 1040 candetermine both a rear of the passageway 1060 and opposing side walls ofthe passageway 1060 that physically interconnect the first wall 1045 andthe thermal barrier 1040. However, other configurations can be used toform the passageway 1060.

The evaporator 326 can be positioned in the passageway 1060 behind thefirst wall 1045, and is in communication with the enclosed space 314through an air flow 1052 between the first opening 1050 and the secondopening 1055. In one embodiment, the passageway includes directionalducts 1090 (e.g., adjacent and inside the second opening 1055 and insidethe container 312). In one embodiment, the passageway 1060 cansequentially include the evaporator 326 and a damper 1075 along thepassageway 1060. The evaporator fan 338 can be operably coupled to thepassageway 1060 anywhere between the first opening 1050 and the secondopening 1055 to move air from the first opening 1050 (e.g., from theenclosed space 314), across a surface of the evaporator 326, past thedamper 1075, and through the second opening 1055 (e.g., to the enclosedspace 314).

In one embodiment, the damper 1075 is positioned adjacent the firstopening 1050 or second opening 1055 and outside the compartment 1010. Insuch a configuration, the damper 1075 can be mounted to the outside ofthe compartment 1010. Alternatively, the damper 1075 can be in thepassageway 1060 between the first opening 1050 and the evaporator 328,adjacent and after the evaporator 328 (e.g., between the evaporator 328and the evaporator fan 338), adjacent and after the evaporator fan 338or between the directional ducts 1090 and the second opening 1055.Regardless of the position in the passageway 1060 of the damper 1075, anactuator 1072 to move the damper 1075 (e.g., between at least threedifferent positions) can be co-located in the refrigerated portion ofthe compartment 1010 (e.g., in the passageway 1060) or operativelycoupled to the damper and positioned in the second ambient position ofthe compartment 1010. Regardless of the location of the actuator 1072,an exemplary damper 1075 can be placed upstream or downstream of theevaporator fan 338.

As shown in FIGS. 10A-10B, an exemplary position of the damper 1075 canbe downstream of the evaporator fan 338 adjacent the first opening andinside the compartment 1010, to reduce or inhibit heat and/or warm airthat is discharged from or moved by the fan 338 during the defrost modefrom exiting via the second opening 1055 to enter the conditioned space.In one embodiment, the damper 1075 is a barrier that is in an openposition when the refrigeration system is in the cooling or heatingmodes, and is moved to a closed position when the refrigeration systemis in the defrost mode.

In one embodiment, the damper 1075 can be positioned in a plurality ofintermediate positions between an open position (e.g., first position)and a closed portion (e.g., second position). Accordingly, in oneembodiment the damper 1075 may include three (3) intermediate positions,seven (7) intermediate positions, 25 intermediate positions or more than75 intermediate positions or the like. Intermediate positions of thedamper 1075 can be used in an operational mode or cooling mode of thetransport refrigeration unit 1010. In one embodiment, intermediatepositions can be used to adjust the air flow volume or air speed betweena high level, first prescribed level, or a 100% level air flow, and alow level, second prescribed level or a 0% air flow.

At least one intermediate position, a plurality of intermediatepositions, or all intermediate positions of the damper 1075 can becorrelated to an air flow level. For example, such a correlation can bedetermined empirically. In one embodiment, the intermediate positions ofthe damper 1075 can be correlated to the transport refrigeration unit1010 modes, operations or capacity (e.g., cooling capacity).

The damper 1075 can be moved (e.g., reciprocally) between a plurality ofintermediate positions using the actuator 1072. The actuator 1072 can bea gear motor, stepper motor, DC motor, electric motor, mechanicalassembly, or the like operatively connected to the damper 1075. Theactuator 1072 can be positioned in anywhere in the container 1030. Forexample, the actuator can be positioned in the first refrigeratedposition (e.g., passageway 1060) or the second ambient portion of thecontainer 1030.

In one embodiment, the damper 1075 can be periodically moved to a knownor prescribed position (e.g., closed) and then stepped to a currentdesired position. In this example, should the damper 1075 include nine(9) equally spaced intermediate positions, driving the actuator 1072 ten(10) steps in a single direction toward the closed position can move thedamper 1075 from an open position and to the closed position. Similarly,driving the damper 1075, five steps away from the closed position wouldposition the damper 50% open.

However, embodiments of the damper are not intended to be so limited.For example, intermediate positions can be unequally spaced. In oneembodiment, a prescribed function or nonlinear function can determinethe intermediate positions. In one embodiment, a plurality ofintermediate portions between the open and closed positions of thedamper 1075 can each use different step sizes (e.g., equal step sizes)such as step sizes a, b, c, respectively, where a>b>c or a<b<c.

In one embodiment, the majority of intermediate positions can be locatedin one portion or section (e.g., 30%, 20%, 10%) of the distance betweenthe open and closed positions. In one embodiment any position orintermediate position of the damper 1075 can be directly reached (e.g.,in one driving action of the actuator 1072). Further, the actuator 1072can operate using a plurality of speeds.

In one embodiment, a current position of a controlled variablepositioned damper 1075 according to embodiments of the application canbe controlled by or have its position reported (e.g., continuously) to acontroller 350. One or more sensors can be operatively coupled to thedamper 1075 and the controller 1050 in order to determine a positionthereof. The sensor can be used to determine which one of a plurality ofoperating positions (e.g., open, intermediate, closed) the damper 1075is occupying. In one embodiment, the sensor can be physically coupled tothe damper 1075 and wirelessly connected to the controller 350.

As shown in FIG. 11, in one embodiment a sensor 51 coupled to the damper1075 can be used to determine its position (e.g., among a plurality orset of open positions and a closed position). For example, one or moresensors 51 can be used to determine a position of a front edge of thedamper 1075. Alternatively, a plurality of sensors S2 can be used tocompare one or more relative positions of a front edge (e.g., corners)and a rear edge (e.g., corners) of the damper 1075.

In one embodiment, a sensor S3 can be positioned on a correspondinglocation in the passageway 1060 and used with the sensor 51 or sensorsS2 to determine a current occupied position (e.g., intermediateposition) of the damper 1075. For example, the sensor S3 can be locatedon a top surface or a bottom surface of the passageway 1060 surroundingthe damper 1075. Alternatively, the sensor S3 can be mounted rigidly ina spaced relationship to the damper 1075 within the compartment 1030.

In one embodiment, a linkage between the actuator 1072 and the damper1075 can be used to determine a position of the damper 1075. Forexample, a sensor S4 mounted on a rotating damper shaft (e.g., 730,730′) can be used to determine an amount of rotation of the linkage,which can be correlated to a position of the damper 1075, to determinethe current position of the damper 1075. However, the exemplary linkagebetween the actuator 1072 and the damper 1075 can include any number ofbearings, connectors, fasteners, shafts, cams, etc. to mechanicallyoperatively couple the actuator 1072 to the damper 1075, each of whichcan be monitored by the sensor S4.

In one embodiment, the sensor S5 can be mounted to the actuator 1072. Asdescribed herein, the actuator 1072 can include a motor, solenoid, cam,an electric motor, a linear actuator, mechanism, piston, power train, ora manual operation. For example, the sensor S5 can be mounted todetermine a relative rotational or linear movement of the actuator 1072that can be correlated to a movement amount of the damper 1075 toidentify a current position within the plurality of positions (e.g.,within a first set of three or more positions) of the damper 1075.Alternatively, a physical position of the sensor S5 can be used todetermine the current position of the damper 1075. According toembodiments of the application, a position of the damper 1075 can bedetermined (directly or indirectly) from sensors that detect movement ora position of the damper 1075 that are operatively coupled to thecontroller 350.

In one embodiment, a plurality of damper units can be implemented ineach of a plurality of ducts such as the directional ducts 1090. In sucha configuration (and other configurations), damper units can control ormodify air flow direction in combination with air flow amounts. Forexample, 4 to 8 individual directional ducts 1090 can be implementedjust inside and adjacent the second opening 1055. However, the number ofdirectional ducts 1090 can be more or fewer. In such a configuration, asingle actuator can be connected to drive all the damper units in unisonbetween each of an open position, a plurality of intermediate positionsand a closed position. Alternatively, two separate actuators can beselectively connected to corresponding adjacent halves of the damperunits in the ducts 1090 or connected respectively to horizontallyalternating damper units in the directional ducts 1090. Alternatively,each damper unit can use a single corresponding actuator unit and sensorS6.

In one embodiment, the damper 1075 can be located adjacent both thefirst opening 1050 and the second opening 1055, and positioned to bedriven by a single actuator or support shaft (not shown). For example,the damper 1075 can include a plurality of horizontal louvers connectedtogether to extend from a top to a bottom (e.g., to cover) of the firstand second openings. A single driving shaft can operate the plurality oflouvers to move among at least one intermediate position, an openposition, and a closed position. In such an embodiment, the damper 1075can be mounted to an outside or inside surface of the compartment 1010.The linkage having the sensor S4 has a prescribed relationship to thedamper position or can be rigidly connected to the damper 1075.

As described herein, in some embodiments of a damper assembly, transportrefrigeration units using the same, and methods for operating atransport refrigeration system can provide a controllable variableposition damper. In one embodiment, a damper position can be correlatedto a transport refrigeration system capacity or a component capacitytherein.

In one embodiment, the controller 350 can correlate position of damper(e.g., damper 775, damper 1075) to air flow reduction. For example, a100% open damper can provide a 100% system air flow, and a closed dampercan provide a 0% system air flow. Each intermediate position of thedamper 1075 can be correlated to a corresponding air flow between0-100%. In one embodiment, a prescribed relationship between air flowand damper position can be determined empirically, for example, for acomponent (e.g., evaporator fan) or a mode of the transportrefrigeration unit 1010. Accordingly, a 25% open damper may result in50% air flow.

Further, in one embodiment, an evaporator fan 1038 can operate in a lowspeed and a high speed. These exemplary speeds can be combined with aplurality of intermediate damper positions of the damper 1075 to rapidlyincrease a controllable variability of air flow in the transportrefrigeration unit 1010 according to embodiments of the application. Inone embodiment, the controller 350 can operate the damper position toprovide better approximation of capacity of the transport refrigerationunit 1010 (e.g., to cargo). For example, a cargo may slowly warm whenoperating the evaporator fan 338 at a low speed and the cargo may coolbelow a required or desired temperature when operating the evaporatorfan 338 at a high fan speed. The controller 1050 can continuouslyprovide a required temperature using embodiments of the application tooperate the evaporator fan 1038 on high speed and operate the damper1075 at an intermediate position. Accordingly, the quality of thedelivered cargo can be increased (e.g., by avoiding cycling thetransport refrigeration unit 1010 to capacities above and below aprescribed capacity correlated to a current cargo).

In one embodiment, the controller 350 can operate a damper position ofthe damper 1075 to provide increased variability of system capacity orgranularity of system capacity. For example, in one embodiment accordingto embodiments of the application, the evaporator fan 1038 can operateat either low speed or high speed, however, movement of the damperbetween a plurality of intermediate positions can provide system coolingcapacities between a corresponding low evaporator fan speed capacity anda corresponding high evaporator fan speed capacity (e.g., within arespective operational mode of the transport refrigeration unit 1010).

In one embodiment, a compressor (e.g., compressor 318) can operate usingmore than one compressor capacity, which can affect a transportrefrigeration unit 1010 capacity. For example, when an exemplarycompressor has two speeds and can operate with two unloaders, theexemplary compressor can provide system 1000 or controller 350 with four(e.g., more than two compressor capacities) compressor capacities. Tobetter match the variable state of the compressor capacity, the damper1075 position may be correlated and/or modified. Thus, movement of thedamper 1075 between a prescribed set of positions including a pluralityof intermediate positions can to provide system cooling capacitiesbetter matched to compressor operations (e.g., within a respectiveoperational mode of the transport refrigeration unit 1010).

In one embodiment, adjusting a damper position of the damper 1075 amongvariably open positions can allow an additional independent adjustmentfor humidity. For example, the damper 1075 position can be moved (e.g.,away from fully open toward closed) to adjust (e.g., slow) the airflowacross the evaporator 326 to adjust humidity (e.g., decrease humidity tomore rapidly dry a cargo). Similarly, a system 1000 capacity can becorrelated to a prescribed cargo or container size. Thus, intermediatedamper positions can be used to adjust capacity to cargo or trailersize. For example, a high speed fan may be correlated to a 53′container. However, alternate container sizes or smaller cargo load mayuse reduced “cooling capacity” (e.g., speed across the evaporator 326)using embodiments of damper assemblies, transport refrigeration unitsand methods for same according to the application.

In one embodiment, confirmation of the correct operation of the damper775 can be determined using a back-up detection of the damper position.For example, the existing return air temperature (RAT) and supply airtemperature (SAT) can be used as a backup to the sensor (e.g., sensorsS1-S6) to indicate/confirm damper opening or closing. In one embodiment,RAT>SAT can be used as a back-up determination that the damper 1075 isopen and RAT approximately equal to SAT (e.g., (RAT−SAT)<threshold) canconfirm or determine the damper 1075 is closed. In one embodiment, in adefrost mode SAT<<RAT can indicate the damper 1075 is open. Further, inthe defrost mode, the temperature relationship of SAT, RAT can varyaccording to a position of the damper 1075 to the SAT, and/or the RAT.For example, the SAT can be determined (e.g., sensors mounted along thepassageway 1060) before or after the closed damper 1075 in the defrostmode. The information regarding the damper 1075 being in theclosed/intermediate/open position can be provided to the controller 1050and/or operator.

Embodiments of the application have been described herein with referenceto controlling air flow or transport refrigeration system capacities.However, embodiments of the application are not intended to be limitedthereby. For example, embodiments of the application can control airdirectional flow, for example by having a front sealing surface of thedamper be against a top, sides or bottom surface of the passageway ordirectional ducts and/or by use of a shape of the damper.

Embodiments of the application have been described herein with referenceto a single damper or damper door. However, embodiments of theapplication are not intended to be so limited. For example, embodimentof the application may be configured to use two or more verticallyspaced dampers or damper doors (e.g., in a fixed prescribed spatialrelationship).

Embodiments of the application have been described herein with referenceto a heat evaporation type heat exchanger. However, embodiments of theapplication are not intended to be so limited. For example, embodimentof the application may be configured to use a heat absorption type heatexchanger. Embodiments of the application can improve transportconditions for transport refrigeration modules and methods thereofrelative to a fixed length economy mode.

In one embodiment of the transport refrigeration unit 10 (e.g., as shownin FIG. 2), the condenser fan 224 can be replaced by a first circulatingfluid heat exchanger and the evaporator fan 228 can be replaced by asecond circulating fluid heat exchanger. The first circulating fluidheat exchanger can be thermally coupled to the condenser heat exchangerunit 222 to remove heat from the coolant and transfer the heat to asecond circulating fluid. The second circulating fluid heat exchangercan be thermally coupled to the evaporator heat exchange unit 226 totransfer heat from a third circulating fluid within the secondcirculating fluid heat exchanger to the coolant within the evaporatorheat exchange unit 226.

The first wall 340 can be insulated and can include a single layer or aplurality of layers (e.g., co-joined). The first wall 340 can include aphysical layer to prevent the flow of conditioned air therethrough.Further, the first wall 340 can have a three dimensional (3D) shape toreduce an overall size of the unit 310. The first wall 340 can include athermal layer or provide a thermal barrier between an ambient portion ofthe unit 310 that is not conditioned and the portion of the unit 310 tobe conditioned, which is not accessible without removing the cargo loadin the container 314 or detaching the unit 310 from the container 314.

The container 12 illustrated in FIG. 1 may be towed by a semi-truck forroad transport. However, those having ordinary skill in the art willappreciate that exemplary containers according to embodiments of theapplication is not limited to such trailers and may encompass, by way ofexample only and not by way of limitation, trailers adapted forpiggy-back use, railroad cars, and container bodies contemplated forland and sea service.

Components of the transport refrigeration unit (e.g., motors, fans,sensors), as known to one skilled in the art, can communicate with acontroller (e.g., transport refrigeration unit 10) through wire orwireless communications. For example, wireless communications caninclude one or more radio transceivers such as one or more of 802.11radio transceiver, Bluetooth radio transceiver, GSM/GPS radiotransceiver or WIMAX (802.16) radio transceiver. Information collectedby sensor and components can be used as input parameters for acontroller to control various components in transport refrigerationsystems. In one embodiment, sensors may monitor additional criteria suchas humidity, species concentration or the like in the container.

Also, it is to be understood that the phraseology and terminology usedherein is for the purpose of description and should not be regarded aslimiting. The use of “including,” “comprising,” or “having” andvariations thereof herein is meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Unlessspecified or limited otherwise, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings. Further, “connected” and “coupled” are not restricted tophysical or mechanical connections or couplings.

While the present invention has been described with reference to anumber of specific embodiments, it will be understood that the truespirit and scope of the invention should be determined only with respectto claims that can be supported by the present specification. Further,while in numerous cases herein wherein systems and apparatuses andmethods are described as having a certain number of elements it will beunderstood that such systems, apparatuses and methods can be practicedwith fewer than the mentioned certain number of elements. Also, while anumber of particular embodiments have been set forth, it will beunderstood that features and aspects that have been described withreference to each particular embodiment can be used with each remainingparticularly set forth embodiment. For example, features and/or aspectsof embodiments described with respect to FIGS. 10A-11 can be used,combined with, or replace aspects and/or features of embodimentsdescribed with respect to FIG. 3, FIGS. 4A-4B, or FIGS. 7-8.

We claim:
 1. A transport refrigeration unit including a compressor, aprimary refrigerant circuit including heat rejection heat exchangerdownstream of said compressor, and a heat absorption heat exchangerdownstream of said heat rejection heat exchanger, the transportrefrigeration unit comprising: a barrier to separate a first portion ofthe transport refrigeration unit to operate in a refrigeratedenvironment from a second portion; at least one damper door in therefrigerated portion, the damper door to move between three or morepositions; and an actuator operatively coupled to move the damper door,the actuator controlling movement of the damper door between an openposition and a closed position and a plurality of intermediate positionsbetween the open position and a closed position; where the plurality ofintermediate positions of the damper door are configured to vary atransport refrigeration unit capacity or a transport refrigeration unithumidity capacity.
 2. The transport refrigeration unit of claim 1, wherethe damper door can be sequentially reciprocally moved between theclosed position and the plurality of intermediate positions or directlymoved to the closed position and each of the plurality of intermediatepositions.
 3. The transport refrigeration unit of claim 2, where theplurality of intermediate positions are equally spaced, spaced in two ormore different linear sections, spaced with changing granularity,non-linearly spaced, spaced without intermediate positions, spacedwithout repeatable intermediate positions or spaced having a prescribedrelationship.
 4. The transport refrigeration unit of claim 1, comprisingat least one sensor on the damper door or the actuator.
 5. The transportrefrigeration unit of claim 1, comprising at least one sensoroperatively coupled to provide a current stepped position of the damperdoor away from a first position.
 6. The transport refrigeration unit ofclaim 5, wherein said at least one sensor comprises first sensor unitspositioned on the actuator, on a support structure of the damper door,on a support shaft of the damper door, on an internal wall of thetransport refrigeration unit, in an air conduit of the transportrefrigeration unit, in a passageway enclosing the damper door, or on thedamper door, second sensor units operatively proximate to correspondingfirst sensor units.
 7. The transport refrigeration unit of claim 6,comprising second sensor units operatively proximate to correspondingfirst sensor units where the first and second sensor units are wirelessor wired and connected to a controller, the controller is configured tooperate the transport refrigeration unit.
 8. The transport refrigerationunit of claim 1, comprising: a passageway to operate in the refrigeratedenvironment between a first opening and a second opening; and the heatabsorption heat exchanger in the passageway, where the damper door iscoupled to the first opening, between the first opening and the heatabsorption heat exchanger between the heat absorption heat exchanger andthe second opening or coupled to the second opening.
 9. The transportrefrigeration unit of claim 1, where the actuator comprises a motor,solenoid, cam, an electric motor, a linear actuator, mechanism, piston,power train, or a manual operation, and where a supply air temperatureand a return air temperature are used to determine a closed damper doorposition or an open damper door position.
 10. The transportrefrigeration unit of claim 1, where the plurality of intermediatepositions of the damper door provides a corresponding variation in airflow.
 11. The transport refrigeration unit of claim 1, where theplurality of intermediate positions of the damper door are used to varysystem capacity in combination with at least one of fan units,compressor units, cargo type, cargo size, container size, economizerunits, or system operational models.
 12. A transport refrigeration unitcomprising: an evaporator connected within the transport refrigerationunit; a damper configured to selectively vary a prescribed air flow incommunication with the evaporator; at least one sensor operativelycoupled to the damper; a controller coupled to the sensor to determinewhen the damper is in an open position, a closed position and pluralityof intermediate positions between the open position and a closedposition; and a damper actuator operatively coupled to the damper, thedamper actuator to move the damper to the open position, the closedposition and the plurality of intermediate positions between the openposition and a closed position; the controller selecting one of theplurality of intermediate positions of the damper to vary a transportrefrigeration unit capacity or a transport refrigeration unit humiditycapacity.
 13. The transport refrigeration unit of claim 12, comprising:a passageway including an inlet for communication with a first portionto be conditioned and an outlet for communication with the first portionto be conditioned; a blower assembly disposed in communication with theinlet and the outlet, the blower assembly configured to generate anairflow from the inlet toward the outlet; and at least one damper bladeto controllably vary the air flow.
 14. The transport refrigeration unitof claim 13, wherein the damper actuator comprises a motor coupled to ashaft and configured to pivot the damper blade between the open positionand the closed position, wherein the transport refrigeration unitincludes a refrigeration mode and a defrost mode, and wherein the damperblade is pivoted to one of said open position and one of the pluralityof intermediate positions to direct air through the outlet in responseto the refrigeration mode, wherein the damper blade is pivoted to theclosed position to inhibit air from flowing through the outlet inresponse to the defrost mode, wherein a first end of the damper bladecontacts an upper portion of the passageway and a second end of thedamper blade contacts a lower portion of the housing when the damperblade is in the closed position, wherein the damper blade extends acrossa width of the passageway and wherein the second end of the damper bladecontacts a stop member when the damper blade is in the open position.15. A method of modifying a transport refrigeration unit including adamper assembly comprising: configuring the damper to operate in aclosed position in a first mode of the transport refrigeration unit; andconfiguring the damper to vary a system capacity in a second mode of thetransport refrigeration unit; wherein a damper actuator comprisesmechanical linkages to pass through a thermal barrier to operativelycouple the damper actuator to the damper, wherein the first mode is adefrost mode and the second mode is a refrigeration mode, wherein thesecond mode the damper is moved among an open position and a pluralityof intermediate positions between the open position and a closedposition to vary a transport refrigeration unit capacity or a transportrefrigeration unit humidity capacity.
 16. The method of claim 15,further comprising providing at least one sensor operatively connectedto the damper assembly.
 17. A transport refrigeration unit including acompressor, a condenser downstream of said compressor, an expansiondevice downstream of said condenser, and an evaporator downstream ofsaid expansion device, the transport refrigeration unit comprising: abarrier to separate a first portion of the transport refrigeration unitto operate in a refrigerated environment from a second portion; theevaporator in a refrigerated portion; at least one damper door in therefrigerated portion; an actuator mechanically coupled to move thedamper door, the actuator is positioned in the second portion, theactuator to move the damper between an open position and a closedposition; wherein the transport refrigeration unit is configured tooperate in a cooling mode and a defrost mode; wherein a position of thedamper door is moved when the transport refrigeration unit is to operateunder conditions where ice can form in the refrigerated portion; whereinthe actuator is accessible via an access panel for the condenser in anambient portion of the transport refrigeration unit.
 18. The transportrefrigeration unit of claim 17, where the actuator comprises a motor andbearing points to support movement of the damper door between the openposition and the closed position.
 19. The transport refrigeration unitof claim 18, wherein the damper door can be moved by manual operation ofa portion of the actuator between the closed position and the openposition.
 20. The transport refrigeration unit of claim 17, where thesecond portion comprises an ambient portion, where the refrigeratedportion of the transport refrigeration unit includes a passagewaybetween an inlet and an outlet, and where the actuator is accessiblefrom the ambient portion of the transport refrigeration unit.
 21. Thetransport refrigeration unit of claim 17, where the transportrefrigeration unit includes an insulated wall between a refrigeratedportion and an ambient portion of the transport refrigeration unit, andcomprising a damper assembly to pass through the insulated wall.
 22. Thetransport refrigeration unit of claim 21, comprising a seal between theactuator and a first end of a damper shaft of the damper assembly. 23.The transport refrigeration unit of claim 17, wherein heat to defrostthe evaporator is provided by operating the transport refrigeration unitin reverse, by resistive heat applied to the evaporator, or by providingheat from the compressor.